Krebs on Security

In-depth security news and investigation

Posts Tagged: dumps

A longtime reader recently asked: “How do online fraudsters get the 3-digit card verification value (CVV or CVV2) code printed on the back of customer cards if merchants are forbidden from storing this information? The answer: If not via phishing, probably by installing a Web-based keylogger at an online merchant so that all data that customers submit to the site is copied and sent to the attacker’s server.

“So, I am trying to figure out how card not present transactions are possible after a breach due to the CVV. If the card information was stolen via the point-of-sale system then the hacker should not have access to the CVV because its not on the magnetic strip. So how in the world are they committing card not present fraud when they don’t have the CVV number? I don’t understand how that is possible with the CVV code being used in online transactions.”

First off, “dumps” — or credit and debit card accounts that are stolen from hacked point of sale systems via skimmers or malware on cash register systems — retail for about $20 apiece on average in the cybercrime underground. Each dump can be used to fabricate a new physical clone of the original card, and thieves typically use these counterfeits to buy goods from big box retailers that they can easily resell, or to extract cash at ATMs.

Instead, online fraudsters turn to “CVV shops,” shadowy cybercrime stores that sell packages of cardholder data, including customer name, full card number, expiration, CVV2 and ZIP code. These CVV bundles are far cheaper than dumps — typically between $2-$5 apiece — in part because the are useful mainly just for online transactions, but probably also because overall they more complicated to “cash out” or make money from them.

“PoSeidon,” a new strain of malicious software designed to steal credit and debit card data from hacked point-of-sale (POS) devices, has been implicated in a number of recent breaches involving companies that provide POS services primarily to restaurants, bars and hotels. The shift by the card thieves away from targeting major retailers like Target and Home Depot to attacking countless, smaller users of POS systems is giving financial institutions a run for their money as they struggle to figure out which merchants are responsible for card fraud.

Image: Cisco.

One basic tool that banks use to learn the source of card data theft involves determining a “common point-of-purchase” (CPP) among a given set of customer cards that experience fraud. When a new batch of cards goes on sale at an online crime shop, banks will often purchase a very small number of their stolen cards to determine if the victim customers all shopped at the same merchant across a specific time period.

This same CPP analysis was critical to banks helping this reporter identify some of the biggest retail breaches on record in recent years, and it is a method heavily relied upon by law enforcement agencies to identify breach victims.

But the CPP approach usually falls flat if all of the cards purchased from the fraud shop fail to reveal a common merchant. More seasoned fraud shops have sought to achieve this confusion and confound investigators by “making sausage” — i.e., methodically mixing cards stolen from multiple victims into any single new batch of stolen cards that they offer for sale.

Increasingly, however, fraudsters selling stolen cards don’t need to make sausage: The victims that are leaking card data are already subsets of restaurant franchises or retail establishments whose only commonality is the branded point-of-sale device which they rely upon to process customer card transactions.

NEXTEP

Card breaches involving POS devices sold by the same vendor are notoriously hard for financial institutions to diagnose because the banks very often have a direct relationship with neither the POS vendor nor the breached restaurant or bar whose customers’ cards were stolen.

What’s more, POS-specific breaches frequently tie back to a subset of customers of a POS vendor who in turn rely on local IT company to install and support the POS systems. The commonality among breached restaurants and bars tends to be those who have relied on a support firm that invariably enables remote access to the POS systems via tools like pcAnywhere or LogMeIn using the same or easily-guessed username and password across many customer systems. Once remotely authenticated to the targeted systems, thieves can upload malware like POSeidon, which is capable of capturing all card data processed by the victim POS.

A few weeks ago, this reporter broke the news that multiple systems run by POS vendor NEXTEP had experienced a breach. The banks were only able to pinpoint NEXTEP systems as the source because the overwhelming number of merchants impacted in that breached happened to be NEXTEP customers who also were part of the Zoup chain of soup restaurants.

“You may have seen the discussions of the ‘PoSeidon’ malware that specifically targeted point of sale systems,” NEXTEP CEO Tommy Woycik said in a follow-up email. “Within thirty-six hours of the point that we learned of the problem we were able to internally use our resources to block further data compromise with most of our customers. We retained and worked with two different sets of consultants to fix all remaining problems and to evaluate, on an ongoing basis, the effectiveness of the fixes.”

Woycik said the company also is investigating why the vast majority of its customers had no compromise of information, but that the hack was limited to a few identified locations. Part of the problem was that some of the breached locations relied on point-of-sale management firms that refused to cooperate in the investigation.

“We have been somewhat hampered in our investigation because some parties involved in the locations that we believe may have been affected have been unwilling to provide us with critical data,” he said.

Lost amid the media firestorm these past few weeks about fraudsters turning to Apple Pay is this stark and rather unsettling reality: Apple Pay makes it possible for cyber thieves to buy high-priced merchandise from brick-and-mortar stores using stolen credit and debit card numbers that were heretofore only useful for online fraud.

To understand what’s going on here, a quick primer on card fraud is probably in order. If you’re a fraudster and you wish to walk into a Best Buy store and walk out with a big screen TV or xBox console on someone else’s dime, you’re going to buy “dumps,” which are data stolen straight off the magnetic stripe on the backs of cards.

Typically, dumps are stolen via malware planted on point-of-sale devices, as in the breaches at brick-and-mortar stores like Target, Home Depot and countless others over the past year. Dumps buyers encode the data onto new plastic, which they then use “in-store” at retailers and walk out with armloads full of high-priced goods that can be easily resold for cash. The average price of a single dump is between $10-$30, but the payoff in stolen merchandise per card is often many times that amount.

When fraudsters want to order something online using stolen credit cards, they go buy what the crooks call “CVVs” — i.e., card data stolen from hacked online stores. CVV stands for “card verification code,” and refers to the three-digit code on the back of cards that’s required for most online transactions. Fraudsters buying CVVs get the credit card number, the expiration date, the card verification code, as well as the cardholder’s name, address and phone number. Because they’re less versatile than dumps, CVVs cost quite a bit less — typically around $1-$5 per stolen account.

So in summary, dumps are stolen from main-street merchants, and are sought after by crooks mainly for use at main street merchants. CVVs, on the other hand, are stolen from online stores, and are useful only for fraud against online stores.

Enter Apple Pay, which potentially erases that limitation of CVVs because it allows users to sign up online for an in-store payment method using little more than a hacked iTunes account and CVVs. That’s because most banks that are enabling Apple Pay for their customers do little, if anything, to require that customers prove they have the physical card in their possession.

Avivah Litan, a fraud analyst with Gartner Inc. explained a blog post published earlier this month that Apple provides banks with a fair amount of data to aid banks in their efforts at “identity proofing” the customer, such as device name, its current geographic location, and whether or not the customer has a long history of transactions with iTunes.

All useful data points, of course, unless the iTunes account that all of this information is based on is hijacked by fraudsters. And as we know from previous stories on this blog, there is a robust trade in the cybercrime underground for hijacked iTunes accounts, which retail for about $8 per account.

Book2Park.com, an online parking reservation service for airports across the United States, appears to be the latest victim of the hacker gang that stole more than a 100 million credit and debit cards from Target and Home Depot. Book2park.com is the third online parking service since December 2014 to fall victim to this cybercriminal group.

Last week, a new batch of credit card numbers [dubbed “Denarius“] went up for sale on Rescator[dot]cm, the cybercrime bazaar that earned infamy by selling tens of millions of cards stolen from Target and Home Depot. Multiple banks contacted by this author acquired a handful of cards from this new batch, and each of those financial institutions found the same pattern: All of the cards they bought had been issued to customers who recently made airport parking reservations at Book2Park.com.

Contacted about the apparent breach, Book2park.com owner Anna Infante said she was not aware that hundreds — if not thousands — of her customers cards were for sale online. But she said a technology firm the company contracts with did recently discover and remove malicious files that were somehow planted on Book2park’s Web server.

“We already took action on this, and we are totally on it,” Infante said. “We are taking all further steps in protecting our customers and reporting this to the proper authorities.”

In December, the same hacker gang began selling card accounts stolen from the Web sites of Park ‘N Fly and OneStopParking.com. The card accounts stolen from OneStopParking and Park ‘N Fly sold for prices between $6 and $13, but the cards taken from Book2Park’s site mostly fetch prices ranging from $12 to $18. This may be because most of the cards were issued by European banks, which tend to sell for more (at least on Rescator’s site). Continue reading →

Over the past year, I’ve spent a great deal of time trolling a variety of underground stores that sell “dumps” — street slang for stolen credit card data that buyers can use to counterfeit new cards and go shopping in big-box stores for high-dollar merchandise that can be resold quickly for cash. By way of explaining this bizarro world, this post takes the reader on a tour of a rather exclusive and professional dumps shop that caters to professional thieves, high-volume buyers and organized crime gangs.

The subject of this post is “McDumpals,” a leading dumps shop that first went online in late April 2013. Featuring the familiar golden arches and the bastardized logo, “i’m swipin’ it,” the site’s mascot is a gangstered-up Ronald McDonald pointing a handgun at the viewer.

Nevermind that this shop is violating a ridiculous number of McDonald’s trademarks in one fell swoop: It’s currently selling cards stolen from data breaches at main street stores in nearly every U.S. state.

Like many other dumps shops, McDumpals recently began requiring potential new customers to pay a deposit (~$100) via Bitcoin before being allowed to view the goods for sale. Also typical of most card shops, this store’s home page features the latest news about new batches of stolen cards that have just been added, as well as price reductions on older batches of cards that are less reliable as instruments of fraud.

I’ve put together a slideshow (below) that steps through many of the updates that have been added to this shop since its inception. One big takeaway from this slideshow is that many shops are now categorizing their goods for sale by the state or region of the victim company.

This was a major innovation that we saw prominently on display in the card shop that was principally responsible for selling cards stolen in the Target and Sally Beauty retail breaches: In those cases, buyers were offered the ability to search for cards by the city, state and ZIP of the Target and Sally Beauty stores from which those cards were stolen. Experienced carders (as buyers are called) know that banks will often flag transactions as suspicious if they take place outside of the legitimate cardholder’s regular geographic purchasing patterns, and so carders tend to favor cards stolen from consumers who live nearby.

The slideshow may make more sense if readers familiarize themselves with a few terms and phrases that show up in the text:

Credit and debit card accounts stolen in a recent data breach at retail giant Target have been flooding underground black markets in recent weeks, selling in batches of one million cards and going for anywhere from $20 to more than $100 per card, KrebsOnSecurity has learned.

Prior to breaking the story of the Target breach on Wednesday, Dec. 18, I spoke with a fraud analyst at a major bank who said his team had independently confirmed that Target had been breached after buying a huge chunk of the bank’s card accounts from a well-known “card shop” — an online store advertised in cybercrime forums as a place where thieves can reliably buy stolen credit and debit cards.

There are literally hundreds of these shady stores selling stolen credit and debit cards from virtually every bank and country. But this store has earned a special reputation for selling quality “dumps,” data stolen from the magnetic stripe on the backs of credit and debit cards. Armed with that information, thieves can effectively clone the cards and use them in stores. If the dumps are from debit cards and the thieves also have access to the PINs for those cards, they can use the cloned cards at ATMs to pull cash out of the victim’s bank account.

At least two sources at major banks said they’d heard from the credit card companies: More than a million of their cards were thought to have been compromised in the Target breach. One of those institutions noticed that one card shop in particular had recently alerted its loyal customers about a huge new batch of more than a million quality dumps that had been added to the online store. Suspecting that the advertised cache of new dumps were actually stolen in the Target breach, fraud investigators with the bank browsed this card shop’s wares and effectively bought back hundreds of the bank’s own cards.

When the bank examined the common point of purchase among all the dumps it had bought from the shady card shop, it found that all of them had been used in Target stores nationwide between Nov. 27 and Dec. 15. Subsequent buys of new cards added to that same shop returned the same result.

On Dec. 19, Target would confirm that crooks had stolen 40 million debit and credit cards from stores nationwide in a breach that extended from Nov. 27 to Dec. 15. Not long after that announcement, I pinged a source at a small community bank in New England to see whether his institution had been notified by Visa or MasterCard about specific cards that were potentially compromised in the Target breach.

This institution has issued a grand total of more than 120,000 debit and credit cards to its customers, but my source told me the tiny bank had not yet heard anything from the card associations about specific cards that might have been compromised as a result of the Target breach. My source was anxious to determine how many of the bank’s cards were most at risk of being used for fraud, and how many should be proactively canceled and re-issued to customers. The bank wasn’t exactly chomping at the bit to re-issue the cards; that process costs around $3 to $5 per card, but more importantly it didn’t want to unnecessarily re-issue cards at a time when many of its customers would be racing around to buy last-minute Christmas gifts and traveling for the holidays.

On the other hand, this bank had identified nearly 6,000 customer cards — almost 5 percent of all cards issued to customers — that had been used at Target stores nationwide during the breach window described by the retailer.

When I mentioned that a big bank I’d spoken with had found a 100 percent overlap with the Target breach window after purchasing its available cards off a particular black market card shop called rescator[dot]la, my source at the small bank asked would I be willing to advise his fraud team on how to do the same?

CARD SHOPPING

Ultimately, I agreed to help in exchange for permission to write about the bank’s experience without actually naming the institution. The first step in finding any of the bank’s cards for sale was to browse the card shop’s remarkably efficient and customer-friendly Web site and search for the bank’s “BINs”; the Bank Identification Number is merely the first six digits of a debit or credit card, and each bank has its own unique BIN or multiple BINs.

According to the “base” name for all stolen cards sold at this card shop, the proprietor sells only cards stolen in the Target breach.

A quick search on the card shop for the bank’s BINs revealed nearly 100 of its customers’s cards for sale, a mix of MasterCard dumps ranging in price from $26.60 to $44.80 apiece. As one can imagine, this store doesn’t let customers pay for purchases with credit cards; rather, customers can “add money” to their accounts using a variety of irreversible payment mechanisms, including virtual currencies like Bitcoin, Litecoin, WebMoney and PerfectMoney, as well as the more traditional wire transfers via Western Union and MoneyGram.

With my source’s newly registered account funded via wire transfer to the tune of USD $450, it was time to go shopping. My source wasn’t prepared to buy up all of the available cards that match his institution’s BINs, so he opted to start with a batch of 20 or so of the more recently-issued cards for sale.